On Sat, Nov 02, 2024 at 10:58:42PM +0100, Florian Weimer wrote: > QEMU hints towards further problems (in linux-user/syscall.c): > > case TARGET_NR_set_robust_list: > case TARGET_NR_get_robust_list: > /* The ABI for supporting robust futexes has userspace pass > * the kernel a pointer to a linked list which is updated by > * userspace after the syscall; the list is walked by the kernel > * when the thread exits. Since the linked list in QEMU guest > * memory isn't a valid linked list for the host and we have > * no way to reliably intercept the thread-death event, we can't > * support these. Silently return ENOSYS so that guest userspace > * falls back to a non-robust futex implementation (which should > * be OK except in the corner case of the guest crashing while > * holding a mutex that is shared with another process via > * shared memory). > */ > return -TARGET_ENOSYS; I don't think we can sanely fix that. Can't QEMU track the robust thing itself and use waitpid() to discover the thread is gone and fudge things from there?
